[all-commits] [llvm/llvm-project] 71fc4b: [X86][SSE] Add ISD::ROTR support

[Simon Pilgrim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 71fc4bbdd2009019acca0f66a7574f97966620fc
      https://github.com/llvm/llvm-project/commit/71fc4bbdd2009019acca0f66a7574f97966620fc
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2021-12-23 (Thu, 23 Dec 2021)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/X86/funnel-shift-rot.ll
    M llvm/test/CodeGen/X86/vector-fshr-rot-128.ll
    M llvm/test/CodeGen/X86/vector-fshr-rot-256.ll
    M llvm/test/CodeGen/X86/vector-fshr-rot-512.ll
    M llvm/test/CodeGen/X86/vector-fshr-rot-sub128.ll

  Log Message:
  -----------
  [X86][SSE] Add ISD::ROTR support

Fix issue in TargetLowering::expandROT where we only attempt to flip a rotation if the other direction has better support - this matches TargetLowering::expandFunnelShift

This allows us to enable ISD::ROTR lowering on SSE targets, which particularly simplifies/improves codegen for splat amount and AVX2 per-element shifts.